My question is based on a search that I have made on the following pages (but I am still to new to scala to succeed in what I want to do):
The purpose of my code is to invoke a method from a generic type and not an instance of a known type.
The following demonstrate the idea:
class A {
def process = {
(1 to 1000).foreach(x => x + 10)
}
}
def getTypeTag[T: ru.TypeTag](obj: T) = ru.typeTag[T]
def perf[T: ru.TypeTag](t: T, sMethodName: String): Any = {
val m = ru.runtimeMirror(t.getClass.getClassLoader)
val myType = ru.typeTag[T].tpe
val mn = myType.declaration(ru.newTermName(sMethodName)).asMethod
val im = m.reflect(getTypeTag(t))
val toCall = im.reflectMethod(mn)
toCall()
}
val a = new A
perf(a, "process")
The code compile perfectly (on a worksheet) but give the following stack at execution:
scala.ScalaReflectionException: expected a member of class TypeTagImpl, you provided method A$A11.A$A11.A.process
at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$JavaMirror$$ErrorNotMember(test-log4j.sc:126)
at scala.reflect.runtime.JavaMirrors$JavaMirror$$anonfun$scala$reflect$runtime$JavaMirrors$JavaMirror$$checkMemberOf$1.apply(test-log4j.sc:221)
at scala.reflect.runtime.JavaMirrors$JavaMirror.ensuringNotFree(test-log4j.sc:210)
at scala.reflect.runtime.JavaMirrors$JavaMirror.scala$reflect$runtime$JavaMirrors$JavaMirror$$checkMemberOf(test-log4j.sc:220)
at scala.reflect.runtime.JavaMirrors$JavaMirror$JavaInstanceMirror.reflectMethod(test-log4j.sc:257)
at scala.reflect.runtime.JavaMirrors$JavaMirror$JavaInstanceMirror.reflectMethod(test-log4j.sc:239)
at #worksheet#.perf(test-log4j.sc:20)
at #worksheet#.get$$instance$$res0(test-log4j.sc:28)
at #worksheet#.#worksheet#(test-log4j.sc:138)
Any idea about how to correct this ?
Many thanks to all
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